1. Field of the Invention
The present invention relates to a safety protection apparatus for automatically interrupting the flow of a fluid, in particular a gas or fuel line, upon the occurrence of a catastrophic fault or alarm condition, including smart sensors, alarms and control systems, such as a seismic disturbance or earthquake or other catastrophe, or from other catastrophic fault conditions such as a gas leak, carbon monoxide, fuel smoke, and other needs (flood, tornado, hurricane, utility emergency or other necessary control).
2. Description of the Prior Art
Various devices are known in the art for shutting off fuel systems in the event of a seismic disturbance or the like. For example, U.S. Pat. No. 4,311,171 to Novi requires a first ball to close a fuel line and at least a second ball, wherein the second ball is mounted within the casing in such a manner that a tremor would cause the second ball to dislodge the first ball from its pedestal. The patent also requires the ball for closing the fuel line to be mounted in a concave cup which is supported by a plurality of ball bearings and includes a concave member, as well as a resilient means (a spring or the like) for biasing the cup against the concave member.
U.S. Pat. No. 4,565,208 to Ritchie requires the inclusion of a track and at least a ball riding in the track, and in addition requires the inclusion of "an obstruction" which causes the ball to leave the track when a seismic disturbance causes the ball to contact the obstruction with sufficient energy, and further requires the obstruction to include an inclined surface which extends over the track and has a height which decreases across the width of the track.
U.S. Pat. No. 4,475,565 to Keller et al. discloses a magnetically actuable shock responsive unit. This unit includes a valve mechanism for shutting off the flow in a fluid line and is operable upon shock induced horizontal displacement of a weight relative to a support to actuate the valve. An electromagnet is provided for providing a separate actuation of the weight. Movement of the weight from its support to the side of the housing causes the weight to engage a movable tube that releases a mechanism that closes the valve.
U.S. Pat. No. 4,903,720 to McGill, one inventor of the present invention, discloses a safety shutoff device usable in any position. An inertia ball engages a first member so as to move the first member from a first position to a second position in response to vibrations or shocks imparted to the housing.
U.S. Pat. No. 5,119,841 discloses another safety shutoff apparatus in which an inertia ball normally rests on an indented surface, and a lever is pivotably mounted, with a permanent magnet mounted beneath the free end of the lever. When a shock or vibration causes the inertia ball to jump onto the lever and roll to ward its free end, the inertia ball is attracted to the permanent magnet so as to cause the lever to be pivoted downwardly.
A further seismic safety valve is described and claimed in U.S. Pat. No. 5,409,031, which together with U.S. Pat. Nos. 4,903,720 and 5,119,841, are incorporated herein by reference.